Think about what you are going to do if you put one down. There are Youtube videos about how to field dress a deer. Decide whether you will butcher it yourself. If so, be prepared to do it quickly in warm weather. If not, figure out where you are going to take it for processing and find out what you need to do. If its warm, you want to get it someplace cool pretty quick.
Also, be sure you know where to aim at the deer to hit vitals at different angles, and remember that its a little different shooting from a tree stand.